- This article is a Community contribution and may include unsupported customizations.

- This is archive documentation, which means it is not supported or valid for recent versions of Zimbra Collaboration.

- This article is a Work in Progress, and may be unfinished or missing sections.

Creating a Domain Alias

If you have a domain domain.com and you want the domain example.com to be an alias for it, so that sending mail to user@example.com is the same as sending mail to user@domain.com (delivered to the same mailbox), you can designate example.com as a domain alias when creating the domain. Starting with ZCS 5.0.16, it is also possible to authenticate using an alias domain (log in as user@example.com), and out-of-office replies notifications can occur for messages sent to addresses in an alias domain (mail to user@example.com will generate an out-of-office reply). The examples assumes domain.com already exists, but example.com does not.

The createAliasDomain command does not set the zimbraMailCatchAllForwardingAddress (which was the sole objective in the pre-5.0.16 alias domain). In order to allow message delivery to the alias domain, it is still necessary to explicitly include a forward to the local target domain.

If the users "john@domain.com", "webmaster@domain.com", and "xyznobody@domain.com" don't exist, and mail arrives for them, it will be delivered to the catchall account "user@domain.com". This will increase the amount of spam delivered, and can lead to being blacklisted. To remove the catchall from an email account, unset the catchall address:

zmprov modifyAccount user@domain.com zimbraMailCatchallAddress ""

Domain Masquerading

If you want mail from user@domain.com or user@zimbra.domain.com to appear to come from user@example.com, you can set the canonical address for the entire domain.

Email to non-existant accounts

Currently we automatically accept email for alias domains and then generate a bounce. This has the potential for backscatter abuse and we'd like to close this hole for hosted and still be able to offer alias domains without adding aliases to each account.